The goals for this project are four fold: 1) to define and correlate the biochemical, mechanical and biological characteristics of scar tissue about tendons and joints; 2) to determine the effects of mechanical stress on biochemical and structural alterations in the scar and correlate these changes with the subsequent biochemical changes; 3) to determine the response of scar to an acute stress and correlate this response with the subsequent biological behavior of the scar and 4) to design a mathematical predictive model. These goals will be obtained by defining the biological activity of scar in man and production of scar in animals for biochemical, mechanical and functional analysis and determination of the effects of various levels of stress on tissue reorganization. The biological activity of scar in man will be determined by frequent recordings in the changes in compliance with the scar in patients. Through the production of scar in animals, we will obtain tissues for biochemical, mechanical and functional analysis. Tissues will be obtained for biochemical analysis of collagen synthesis and degradation and engineering analysis of the mechanical properties of the scar by measuring stress-strain, stress-relaxation, creep, mechanical recovery and length recovery properties of the normal and scarred tissues. The mechanical properties of scar in man will be determined by their response to a load for a short period of time. This acute response will be correlated with the subsequent biological activity of their scars. Utilizing the mechanical data obtained from our animal and human experiments, we will design a mathematical model which could allow prediction of scar behavior. This predictive model will be applied to our patients to determine its validity.